Aligning vertebral bodies

ABSTRACT

Misaligned bones on opposite sides of a joint are aligned using a first rigid extension securable to one of the misaligned bones using a particular surgical approach, and a second rigid extension having a contacting surface positionable in contact with the other the two misaligned bones from the same surgical approach. The first and second rigid extensions are moved with respect to each other using a lever, whereby a pulling force is exerted on one of the bones, and a pushing force on the other, thereby aligning the first and second misaligned bones.

CROSS REFERENCE TO RELATED APPLICATIONS

This Patent Application is a continuation of U.S. patent applicationSer. No. 13/483,558, filed May 30, 2012 (published as U.S. Pat. Pub. No.2013-0325071), which is incorporated by reference herein in its entiretyfor all purposes.

FIELD OF THE INVENTION

The invention relates to aligning bones of the body, and moreparticularly to reducing adjacent vertebrae and realigning the vertebralcolumn, for example to correct spondylolisthesis.

BACKGROUND

Bones, bony structures and tissue are susceptible to a variety ofweaknesses that can affect their ability to provide support andstructure. Weaknesses in bony structures may have many causes, includingdegenerative diseases, tumors, fractures, and dislocations. Advances inmedicine and engineering have provided doctors with a plurality ofdevices and techniques for alleviating or curing these weaknesses.

In some cases, an anterior or posterior displacement of a vertebra withrespect to an adjacent vertebra takes place, giving rise to a disordertermed spondylolisthesis. Resultant pressure on nerves can produce pain,stiffening of the back, changes in gait, and muscular atrophy, forexample.

Conservative approaches may include physical therapy and treatment withNSAIDs such as acetaminopyhen. Spinal decompression through, forexample, laminectomy or non-surgical methods may be employed.Additionally, a fusion may be carried out, for example a posterolateralfusion of adjacent vertebrae.

SUMMARY

In accordance with the disclosure, a device for therapeutically aligningtwo misaligned vertebral bodies on opposite sides of a joint, comprisesa first rigid extension securable to a first of the misaligned bonesusing a single approach selected from the group consisting of leftlateral approach, right lateral approach, anterior approach, andposterior approach; a second rigid extension having a contacting surfacepositionable in contact with the second of the two misaligned bones fromthe approach selected for securing the first rigid extension, the secondrigid extension moveable with respect to the first rigid extension whenthe first rigid extension is secured to the first of the misalignedbones and the second rigid extension is positioned in contact with thesecond of the two misaligned bones; and a lever configured to lever thefirst rigid extension with respect to the second rigid extension to movethe first rigid extension with respect to the second rigid extension, tothereby exert a pulling force on the first of the two misaligned bones,and a pushing force on the second of the two misaligned bones, aligningthe first and second misaligned bones.

In embodiments thereof, the first and second misaligned bones arevertebrae; the device further includes an intervertebral spacer, thefirst rigid extension securable to the intervertebral spacer, theintervertebral spacer connected to the first of the misaligned bones;and the intervertebral spacer is formed in two segments, each segmentattachable to one of the first or second misaligned bones, the segmentsmoveable with respect to each other when attached to a respectivemisaligned bone.

In other embodiments thereof, the segments moveable in ratchetingengagement with respect to each other; the lever applies leverage usinga rotatable thread; the first rigid extension is securable to themisaligned bone using a threaded fastener; the first rigid extension isa plate; the plate forms a levered connection between the first andsecond misaligned bones; the first rigid extension extends around thefirst misaligned bone to contact a portion of the first misaligned bonewhich faces an approach different from the approach selected; and one ofthe first or second misaligned bones is the sacrum.

In yet further embodiments thereof, the lever is a screw having threadsconfigured to engage bone on a first end, and threads configured toengage a nut on a second, opposite end, the nut rotated about the secondend moves the second rigid extension and to thereby lever the first andsecond misaligned bones into alignment; the device further includes anintervertebral spacer; and the intervertebral spacer is expandable toincrease a distance between the first and second misaligned bones.

In another embodiment of the disclosure, a device for therapeuticallyaligning two vertebrae, comprises a first rigid extension securable to afirst of the vertebrae using a single approach selected from the groupconsisting of left lateral approach, right lateral approach, anteriorapproach, and posterior approach; a second rigid extension having acontacting surface positionable in contact with the second of the twovertebrae from the approach selected for securing the first rigidextension, the second rigid extension moveable with respect to the firstrigid extension when the first rigid extension is secured to the firstof the vertebrae and the second rigid extension is positioned in contactwith the second of the two vertebrae; a lever configured to lever thefirst rigid extension with respect to the second rigid extension to movethe first rigid extension with respect to the second rigid extension, tothereby exert a pulling force on the first of the two vertebrae, and apushing force on the second of the two vertebrae, aligning the first andsecond vertebrae; and a fastener configured to maintain the first andsecond vertebrae in relative alignment.

In embodiments thereof, the device further includes an intervertebralspacer connectable to at least one of the first and second rigidextensions during alignment of the vertebrae, and connectable to bothvertebrae to maintain the vertebrae in relative alignment; and the firstrigid extension forming a first portion of an intervertebral spacer, thesecond rigid extension forming a second portion of an intervertebralspacer, the first and second portions mateably engageable andmaintainable in relative mutual engagement using a ratchet.

In a further embodiment of the disclosure, a method for therapeuticallyaligning two misaligned bones on opposite sides of a joint, comprisessecuring a first rigid extension to a first of the misaligned bonesusing a single approach selected from the group consisting of leftlateral approach, right lateral approach, anterior approach, andposterior approach; contacting the second of the misaligned bones with asecond rigid extension, the second rigid extension having a contactingsurface positionable in contact with the second of the two misalignedbones from the approach selected for securing the first rigid extension,the second rigid extension moveable with respect to the first rigidextension when the first rigid extension is secured to the first of themisaligned bones and the second rigid extension is positioned in contactwith the second of the two misaligned bones; and levering the firstrigid extension with respect to the second rigid extension using a leverconfigured to move the first rigid extension with respect to the secondrigid extension, to thereby exert a pulling force on the first of thetwo misaligned bones, and a pushing force on the second of the twomisaligned bones, aligning the first and second misaligned bones.

In embodiments thereof, the method further includes inserting anintervertebral spacer between the two misaligned bones; and furtherincludes connecting the intervertebral spacer to the first of themisaligned bones; and applying the lever between the intervertebralspacer and the second of the misaligned bones.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the present invention, and theattendant advantages and features thereof, will be more readilyunderstood by reference to the following detailed description whenconsidered in conjunction with the accompanying drawings wherein:

FIG. 1 is a diagram of a joint of a body;

FIG. 2 is a diagram of the joint of FIG. 1, misaligned;

FIG. 3 is a diagram of the joint of FIG. 1, and a cross-section of aconnected plate and spacer of the disclosure;

FIG. 4 depicts the joint of FIG. 1, aligned using the plate and spacerof FIG. 3;

FIG. 5A depicts the joint of FIG. 1, and a cross section of a spacer,plate, and tool of the disclosure

FIG. 5B is a diagram of the joint of FIG. 1, the joint having beenaligned using the spacer, plate, and tool of FIG. 5A;

FIG. 6 is a diagram of the joint of FIG. 1, and the spacer and plate ofFIG. 5B secured to the joint using fasteners, from a cross-section;

FIG. 7 is a diagram of the joint of FIG. 1, and a top view of a reachingtool and plate of the disclosure;

FIG. 8 depicts the joint and device of FIG. 7, in a cross-section;

FIG. 9 depicts the joint and device of FIG. 8, the joint aligned usingthe device of FIG. 8;

FIG. 10 is a diagram of the joint of FIG. 1, and a cross-section ofspacer of the disclosure having two ratcheting segments;

FIG. 11 depicts the joint and device of FIG. 10, the joint aligned bythe device of FIG. 10;

FIG. 12 is a cross-section of a segmented spacer of the disclosure;

FIG. 13 depicts the spacer of FIG. 12, the segments mutually secured bya fastener;

FIG. 14 is a diagram of the joint of FIG. 1, a cross-section of aratcheting spacer of the disclosure, and an indication of an applicationof a force to align the joint;

FIG. 15 is a diagram of the joint of FIG. 1, and a spacer of thedisclosure, and an indication of an application of a force to align thejoint;

FIG. 16 is a diagram of the joint of FIG. 1, and a cross-section of aspacer and tool in accordance with the disclosure;

FIG. 17 depicts the joint and device of FIG. 16, the device havingaligned the joint;

FIG. 18 depicts the joint and spacer of FIG. 17, the spacer secured tothe aligned joint;

FIG. 19 is a diagram of the joint of FIG. 1, and a cross-section of aspacer and tool of the disclosure;

FIG. 20 is a diagram of the joint of FIG. 1, and a reaching plate of thedisclosure;

FIG. 21 is a diagram of the joint of FIG. 1, and a hinged plate andlever of the disclosure;

FIG. 22 is a diagram of the joint of FIG. 1, and a segmented spacer andlever of the disclosure;

FIG. 23 is a diagram of the joint and device of FIG. 22, the jointhaving been aligned by applying the lever to the device;

FIG. 24 depicts the joint and device of FIG. 23, the joint having beenaligned by applying the lever to a segment and to the joint;

FIG. 25 depicts the joint and device of FIG. 24, the segments joined bya fastener;

FIG. 26 is a diagram of the joint of FIG. 1, and a cross-section of aspacer and plate of the disclosure;

FIG. 27 depicts the joint and spacer of FIG. 26, the joint having beenaligned by the plate, and the spacer secured to both sides of the jointusing fasteners;

FIG. 28 is a diagram of the joint of FIG. 1, and a spacer of thedisclosure;

FIG. 29 depicts the spacer and joint of FIG. 28, the joint having beenaligned by the spacer;

FIG. 30 is a diagram of the joint and spacer of FIG. 28, and across-section of a plate of the disclosure, the spacer and platecooperative to align the joint;

FIG. 31 depicts a joint of the body, in this example the L5 and S1vertebrae, and a cross-section of a plate of the disclosure connected toboth vertebrae;

FIG. 32 depicts the joint of FIG. 31, aligned by the plate, the platefurther secured to the joint;

FIG. 33 is a diagram of the joint of FIG. 31, and a cross-section of aplate and fastener of the disclosure;

FIG. 34 depicts the joint and device of FIG. 33, the joint having beenaligned by the device, the fastener shortened after use;

FIG. 35 is a diagram of the joint of FIG. 1, and a fastener of thedisclosure;

FIG. 36 depicts the joint and fastener of FIG. 35, the joint having beenaligned by the fastener;

FIG. 37 is a diagram of the joint of FIG. 1, and a ratcheting device ofthe disclosure connected to each side of the joint;

FIG. 38 depicts the joint and device of FIG. 37, the joint having beenaligned by the device;

FIG. 39 is a diagram of the joint of FIG. 1, and a cross-section of asegmented spacer of the disclosure;

FIG. 40 depicts the joint and spacer of FIG. 39, the joint secured inalignment, and distracted, using the device of FIG. 39;

FIG. 41 is a diagram of the joint of FIG. 1, and a cross-section of asegmented spacer having three mateable portions, including opposedsegments and a wedge shaped spacer;

FIG. 42 depicts the joint and device of FIG. 41, the spacer having beeninserted between the opposed segments, and the joint, opposed segments,and spacer maintained in alignment by fasteners and a mating engagementbetween the opposed segments and the spacer;

FIG. 43 depicts the joint and device of FIG. 40, the opposed segmentsshaped to reduce an angle formed between bones of the joint;

FIG. 44 depicts the joint and device of FIG. 40, the opposed segmentsshaped to increase an angle formed between bones of the joint;

FIG. 45 depicts a diagram of the joint of FIG. 1, and an expandablespacer, plate, and reaching tool of the disclosure;

FIG. 46 depicts the spacer and device of FIG. 45 in an expandedconfiguration, distracting bones of the joint, the joint having beenaligned by the spacer, plate, and reaching tool;

FIG. 47 is a diagram of the joint of FIG. 1, and a cross-section of aspacer, angled plate, and fastener of the disclosure;

FIG. 48 depicts the joint and device of FIG. 47, the joint having beenaligned using the device, the fastener having been shortened after use;

FIG. 49 is a diagram of the joint of FIG. 1, and a cross-section ofspacer, integrated plate, and fastener of the disclosure;

FIG. 50 depicts the joint and device of FIG. 49, the joint having beenaligned by the device, the fastener shortened after use;

FIG. 51 is a diagram of the joint of FIG. 1, a cross-section of a spacerof the disclosure with ramped segments, and an indication of anapplication of force to align the joint;

FIG. 52 depicts the joint and spacer of FIG. 51, the joint having beenaligned using the spacer, the spacer segments fastened together afteralignment;

FIG. 53 is a diagram of the joint of FIG. 1, and a cross-section of anadjustable segmented spacer of the disclosure, the spacer including arotatable screw operative to align the segments;

FIG. 54 depicts the joint and spacer of FIG. 53, the joint having beenaligned using the spacer, the segments of the spacer fixed by afastener;

FIG. 55 is a side view of a combined plate, spacer, and fasteners of thedisclosure;

FIG. 56 is a perspective view from the top of the device of FIG. 55;

FIG. 57 is a side view of an alternative combined plate, spacer andfasteners of the disclosure;

FIG. 58 is top perspective view from the top of the device of FIG. 57;

FIG. 59 is an alternate top perspective view from the top of the deviceof FIG. 57;

FIG. 60 is a side view of a mateable plate and spacer of the disclosure;

FIG. 61 is a perspective view of the device of FIG. 60;

FIG. 62 is a side view of the device of FIG. 60, the plate and spacermutually assembled in conforming relationship;

FIG. 63 is a front perspective view of a combined plate and spacer ofthe disclosure;

FIG. 64 is a front perspective view of a combined plate and spacer ofthe disclosure, the plate provided with a shaped projection;

FIG. 65 is a perspective illustration of spacer of the disclosure formedof mateable segments;

FIG. 66 is a perspective view of the spacer of FIG. 65, the segmentsmated;

FIG. 67 is a top view of the device of FIG. 65;

FIG. 68 is a top view of the device of FIG. 66;

FIG. 69 is a back view of a combined spacer and plate in two segments,the segments slidingly engageable along an A-P axis;

FIG. 70 is a side view of the device of FIG. 69, the segments partiallyslidingly engaged;

FIG. 71 is a perspective view of the device of FIG. 70;

FIG. 72 is a side view of a combined spacer and plate in two segments,the segments slidingly engageable along a lateral axis;

FIG. 73 is a perspective view of the device of FIG. 72;

FIG. 74 is a side view of a combinable spacer, plate, and fasteners ofthe disclosure, the plate provided with a shaped projection, thefasteners disposed at an angle;

FIG. 75 is a side view of a combinable spacer, plate, and fasteners ofthe disclosure, the plate provided without the shaped projectionillustrated in FIG. 74, the fasteners disposed at an angle;

FIG. 76 is a bottom perspective view of a combinable spacer, plate, andfasteners of the disclosure, the plate provided with a shapedprojection, the fasteners disposed at a converging angle;

FIG. 77 is a top perspective view of the device of FIG. 76;

FIG. 78 is a front view of the device of FIG. 74, illustrating lockingpins;

FIG. 79 is a side view of the device of FIG. 74, implanted within aspine;

FIG. 80 is an illustration of an insertion and alignment tool inaccordance with the disclosure;

FIG. 81 depicts a side view of the tool of FIG. 80 gripping the deviceof FIG. 74;

FIG. 82 depicts the tool and device of FIG. 81, the tool having insertedthe device into a spine, the device fastened to the Si vertebra;

FIG. 83 depicts the tool and device of FIG. 81 having aligned vertebraeof the spine;

FIG. 84 depicts the tool and device of FIG. 83, the device fastened tothe L5 vertebra;

FIGS. 85A-85C depict a method of inserting a spacer in accordance withthe disclosure;

FIG. 86 depicts a side view of a combinable spacer, plate and fastenersof the disclosure, the plate provided with an upper lip; and

FIG. 87 depicts a joint of the body, in this example the L5 and S1vertebrae, and a cross-section of an alternative plate of the disclosureconnected to both vertebrae.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

As required, detailed embodiments are disclosed herein; however, it isto be understood that the disclosed embodiments are merely examples andthat the systems and methods described below can be embodied in variousforms. Therefore, specific structural and functional details disclosedherein are not to be interpreted as limiting, but merely as a basis forthe claims and as a representative basis for teaching one skilled in theart to variously employ the present subject matter in virtually anyappropriately detailed structure and function. Further, the terms andphrases used herein are not intended to be limiting, but rather, toprovide an understandable description of the concepts.

The terms “a” or “an”, as used herein, are defined as one or more thanone. The term plurality, as used herein, is defined as two or more thantwo. The term another, as used herein, is defined as at least a secondor more. The terms “including” and “having,” as used herein, are definedas comprising (i.e., open language).

With reference to FIG. 1, a healthy pair of vertebrae 300, 302 arediagrammatically illustrated. Although adjacent vertebrae are notidentical in the body, to simplify an understanding of an operation ofdevices and methods of the disclosure, a centrally disposed dotted line304 represents a natural overlapping of bones. The disc annulussurrounding the nucleus pulposus is diagrammatically illustrated as disc306, positioned in alignment with both vertebrae. In FIG. 2, vertebrae300, 302 are relatively displaced, representing a patient conditionaddressed by the disclosure, for example degenerative fibrocartilage,malignancy, herniation, protrusion, spondylolysis, spondylolisthesis,spinal stenosis, or degenerative disc disease. While one vertebra 300appears to be oriented in an upper, or superior location with respect tothe other vertebra 302, it should be understood that within the body,superior, inferior, or both bones may be displaced, and that a superioror inferior position of adjacent bones should not be assumed within thedisclosure. In addition, a displacement may be anterior, posterior, orlateral.

In the various embodiments described herein, the spine and vertebrae aredescribed as the bones to be aligned. However, it should be understoodthat the methods and devices of the disclosure are readily applied oradapted to be used with other bones of the body, for example in size andshape. Such other bones include the joints of the fingers, hand, wrist,elbow, shoulder, hip, knee, ankle, foot, or toes. Non-jointed tissue,such as bony plates, for example misaligned after trauma, may also bealigned as described herein. Accordingly, the disclosure should beconsidered in light of other bones and tissue, throughout.

In various embodiments, the devices and methods of the disclosureprovide solutions for treating diseases of the spine, for example,isthmic spondylolisthesis, from a single approach, such asadvantageously an anterior approach. This avoids a requirement of anapproach through two separate aspects of the body, for example also aposterior approach. This reduces trauma to the patient, recovery time,time to complete the surgical procedure, risk, and cost. While ananterior approach is possible, it should be understood that a lateral orposterior approach is similarly possible, while retaining the advantageof aligning bones of a joint from a single approach, including only oneof a left lateral approach, a right lateral approach, an anteriorapproach, or a posterior approach.

In FIG. 3, an intravertebral spacer 5000 engages one or more fasteners,for example bone screws 200, for example by passing a polyaxial screwthrough an aperture, not shown, or through some other configurationunderstood within the art. In this manner, a position of spacer 5000 maybecome fixed with respect to one or more vertebrae, at least for asufficient period of time for healing and or fusion between the body andthe spacer to take place, for example through bony ingrowth. Spacer 5000may be provided with spaces, channels, texture, or other structure whichencourages bone ingrowth, and may further be provided with therapeuticsubstances which encourage bone growth.

With further reference to FIG. 3, an assembly in accordance with thedisclosure includes a plate 400, fasteners or screws 200, 202, and anintervertebral spacer 5000. Spacer 5000 is secured to a vertebra 300using one or more bone screws 200 or other fastener. It should beunderstood that while a bone screw 200 is illustrated in the drawings,for clarity, any fastener suitable for connecting an implant to a bonemay be used, including adhesive, as would be understood by one skilledin the art. In this configuration, vertebra 300 is closer to thesurgical approach than vertebra 302. For example, in an anteriorapproach, vertebra 300 is shifted anteriorly with respect to vertebra302. In a lateral or posterior approach, plate 400 would be applied tothe more lateral or posterior vertebra, respectively.

Plate 400, in accordance with this and other embodiments of thedisclosure, may have a flat, rectangular or bar shape such as isillustrated in the drawings, for clarity, or may be contoured and orcurved, or shaped to closely conform, to the body tissue to which it isattached. In some embodiments, the plate 400 is rigid, while in otherembodiments, the plate 400 can be flexible or bendable. In someembodiments, the plate 400 is configured such that in an unstressedstate, the plate 400 is flat, while in a stressed state, it is curved.

After plate 400 is secured to vertebra 300, a screw 202 or otherfastener configured to perform a like function, is connected betweenplate 400 and spacer 5000. Screw 202 is rotatably connected to plate 400whereby as screw 202 is rotated, spacer 5000 is drawn closer to plate400. Herein, screws should be considered as levers; accordingly, screw200 functions as a lever to facilitate movement of one vertebra withrespect to another. Vertebra 302, being connected to spacer 5000, islikewise drawn closer to plate 400 as screw 202 is rotated, the assemblythereof ultimately causing the therapeutically correct disposition ofvertebrae 300, 302 shown in FIG. 4. As is the case with this and otherembodiments of the disclosure, after correction, the assembly may bepermanently left in the body, or may be removed after a therapeuticperiod of time.

Referring now to FIGS. 5A, 5B, and 6, vertebrae 300 and 302, as well asassociated ligaments 308, are relatively displaced. In this embodiment,an expanding spacer 5002 is positioned between vertebrae 300, 302, forexample after removal of all or part of intervertebral tissue, or disc306A. In this illustration, an additional vertebral level is shown,including vertebra 300A. It should be understood in all embodimentsherein that more than one level may be corrected using methods anddevices of the disclosure. For example, multiple plates may be used, orlonger plates spanning more than one level.

In FIGS. 5A, 5B, and 6, spacer 5002 may be of any known or hereinafterinvented type, including spacers having, for example, mechanical orhydraulic mechanisms of expansion. Vertebra 302 is connected to plate400 with bone screw 200. In one embodiment, spacer 5002 is connected toplate 400, to ensure that spacer 5002 remains in position with respectto vertebra 302, although this is not needed in all cases. For example,spacer 5002 may be separately engaged with vertebra 302. Tool 6000includes a brace 6002 and a driver 6004 moveably connected to brace6000. Brace 6000 is releasably engageable with plate 400 at connector6006.

To correct an alignment of the spine, driver 6004 is moved with respectto brace 6002, for example through a threaded, hydraulic, motor, orother moveable attachment between driver 6004 and brace 6002. It shouldbe understood that herein, drawings are not necessarily to scale, andthat portions of spacers, plates, their assemblies, or insertion andreduction tools may be sized to be inserted in their entirety, or asportions to be assembled, through a minimally invasive incision orthrough one or more percutaneous punctures, for example using anendoscope or cannula. As brace 6002 is connected with plate 400, amovement in the direction of arrow “A” in FIG. 5A causes a displacementin the direction “A” of vertebra 300 and associated ligaments 308. Priorto, during, or after movement of vertebra 300, spacer 5002 may beexpanded to dispose vertebrae 300, 302 at a correct relative distance,and to provide further stability to the spine. In FIG. 6, tool 6000 isdetached, and if needed, an additional bone screw 200 may connect plate400 and vertebra 300. One or more screws 200 may alternatively passthrough plate 400, spacer 5002, and or vertebra 300. In an alternativeembodiment, plate 400 is not used, and brace 6002 is releasablyconnectable to expanding spacer 5002.

With reference to FIGS. 7-9, an assembly of the disclosure includes atool 6010 cooperative with plate 400, attached to vertebra 300 by screws200. Tool 6010 includes a chassis 6012 extendable around a vertebra, andmoveably attached to plate 400. In some embodiments, the chassis 6012can be formed of multiple pieces, or of a single piece. Moreparticularly, plate 400 attaches to a first vertebra 300, extendsproximate a second vertebra 302 which it is desired to reduce intoalignment with the first vertebra 300. Chassis 6012 includes one or moreextensions attached to plate 400, extending to engage vertebra 302 abouta side of vertebra 302 opposite to a location of plate 400, to therebyat least partially encircle vertebra 302 to effect a positiveengagement. It should be understood, however, that chassis 6012 mayfrictionally engage vertebra 302 along a side surface of vertebra 302,or may be connected to vertebra 302 with one or more fasteners.

In the embodiment shown, screw 202 threadably engages chassis 6012 androtatably contacts plate 400, whereby as screw 202 is turned, chassis6012 is pushed away from plate 400, thereby drawing vertebra 302 intoalignment with vertebra 300. When a desired alignment is accomplished,vertebra 302 may be attached to plate 400 to maintain the alignment, orvertebra 302 may be fastened to spacer 5000, or to vertebra 300, by anyother known or hereinafter invented means, if needed. Once vertebra 302is sufficiently stable in its new disposition, tool 6010 may be removed.

In FIGS. 10 and 11, an assembly of the disclosure includes a spacer 5010which is formed of two mating portions 5012, 5014, and forms, in theillustrated embodiment, an angular external profile corresponding to adesired disposition of adjacent vertebrae 300, 302. It should beunderstood that the illustrated concept applies equally to non-angularor other external profiles. Mating portions 5012, 5014 are provided withserrations, teeth, or other interlocking engagements 5016, 5018, wherebywhen mating portions 5012, 5014 are overlapped completely or to adesired extent, a relative position of mating portions 5012, 5014 isfostered, particularly when mating portions 5012, 5014 are pressedtogether, for example between vertebrae 300, 302, by natural compressionand associated ligaments 308 (not shown). Mating portions 5012, 5014 mayalso be secured together by a fastener, including a screw or adhesive.

In FIGS. 10-11, interlocking engagements 5016, 5018 have the form oframped teeth, whereby a mutual sliding engagement, advantageously in adirection of therapeutic alignment of vertebrae 300, 302, isfacilitated, but discouraged in a direction away from therapeuticalignment, as may be seen in FIGS. 10-11. A tool 6018, diagrammaticallyillustrated in FIG. 10, urges, translates, or pushes the vertebra 300 ina desired direction indicated by arrow “A”. Tool 6018 may be amechanical device, for example as described within this disclosure, ormay be a medical practitioner's hand.

In an embodiment illustrated in FIGS. 12-13, mating portions 5012, 5014may or may not have interlocking engagements, as shown, but are securedin mutual engagement by a fastener, such as screw 202, which isadvantageously the same screw as used to manipulate mating segment 5014in FIG. 10. Screw 202 may advantageously be passed through a firstvertebra 300 and threadably fastened into a second vertebra 302.

Tool 6018, diagrammatically illustrated in FIG. 14, may be configuredand or used to engage both spacer 5000 and vertebra 300, advancing bothtogether until a therapeutic alignment is attained. After reduction,vertebrae 300, 302 and spacer 5000 may be secured as described elsewherewithin the disclosure.

In FIG. 15, vertebra 300 is reduced in sliding engagement with spacer5000. After reduction, natural or induced compression, for example bycompression due to body weight, or engagement with bone screws, promotesinsertion of textured surface or projections 5020 with bone or bodytissue, securing a position of spacer 5000 and relative alignment ofvertebrae 300, 302.

In FIG. 16, an assembly of the disclosure includes instrument or tool6020, used to reduce vertebra 300 in cooperation with spacer 5030. Abrace 6022 abuts or connects with spacer 5030, which may be adapted tosecurely engage brace 6022 during reduction. In the example of FIGS.16-18, a threaded connection 6024 is used, although other types ofreleasable mechanical abutments or interlocks may be used. Once brace6022 is connected with spacer 5030, it may serve to align and guide apush rod 6026, slideably connected to brace 6022 by a guide 6028, inthis embodiment a guide ring attached to brace 6022 through which pushrod 6026 slideably passes. An engagement surface 6030 is sized andshaped to move within the body, securely contact body tissue, and urgebones into alignment when push rod 6026 is pushed towards body tissue.Once vertebrae 300, 302 are aligned, tool 6020 may be disconnected fromspacer 5030 and removed from the body. In one embodiment, tool 6020 issized and dimensioned to be used through a minimally invasivepercutaneous opening in the skin, or using endoscopic techniques.

As with the embodiment of FIGS. 16-18, the assembly of FIG. 19 engages atool to a spacer, to anchor and orient a tool for displacing andrealigning a bone. In the embodiment of FIG. 19, tool 6032 is releasablyconnected to spacer 5000, in this embodiment with screw 202, andincludes a lever 6034 which transmits a displacement force to anadjacent vertebra 302. A threaded adjuster 6036 includes a screw 6038rotatably mounted to a guide 6040, screw 6038 operative to advance anengagement surface 6042 to contact and move vertebra 300. As resistanceis imparted to tool 6032, force is transferred to screw 202, and arotational moment of tool 6032 is transferred to lever 6034. In thismanner, the vertebrae 300, 302 to be relatively aligned share a loadforce, and are each displaced to an extent, in opposite directions. Thisis further advantageous at least for the reasons that the tool isstabilized, and a displacement force imparted by tool 6032 is sharedbetween spacer 5000 and vertebra 302. In some embodiments, a biasingmember, such as for example an optional spring 6044, may advantageouslybe included to bias engagement surface 6042 in a direction of vertebra300. Additionally or alternatively, the spring 6044 may limit an extentof force imparted to vertebra 300 by screw 202 and engagement surface6042, by enabling screw 6038 to move in an opposite direction to anapplied force against vertebra 300. In other embodiments, the screw 6038acts on its own without the assistance of a biasing member, such asspring 6044.

With reference to FIG. 20, an assembly of the disclosure includes aplate 410 which has one or more guide extensions 412 operative tomaintain a relative alignment of plate 410 and vertebra 302 as vertebra300 is reduced. More particularly, one or more screws 412 may be used todraw vertebra 302 towards a conforming engagement with plate 412.Concomitantly, an upper portion 414 of plate 410 contacts vertebra 300,which is displayed in a manner such as is illustrated in FIG. 19. Whenscrews 412 are fully seated, plate 410 is in conforming engagement withvertebra 300 and 302, upper portion 414 having urged vertebra 300 intoalignment with vertebra 302, as shown. Guide extensions 412, extendingfor example on opposing sides of vertebra 302, may be secured tovertebra 302 to maintain a lateral alignment of plate 410 with respectto vertebra 302. Upper portion 414 may be secured to vertebra 300, or asshown, may moveably contact vertebra 300, allowing an extent of naturalmovement between vertebrae 300, 302.

In FIG. 21, an assembly of the disclosure includes tool 6050 having alever 6052 pivotally connected to plate 418 at hinge 6054. Plate, 418 isconnected to vertebra 302 by a fastener, such as one or more screws 200.A lever screw 6056 is moveably connected to lever 6052, and is connectedto vertebra 300. As lever 6052 is pivoted, for example by application ofa manual or mechanical force, vertebra 300 is moved correspondingly.When a desired alignment of vertebra 300 is attained, tool 6050 andplate 418 may be removed. Alternatively, hinge 6054 may be disassembled,and plate 418 may remain in the body. In such an embodiment, plate 418may be configured to fuse vertebrae 300, 302, for example by beingtaller than illustrated, wherein screw 200 may be passed through plate418 into vertebra 300. In another alternative, screw 6056 may be seatedto secure lever 6052 against vertebra 300. An extending portion 6058 oflever 6052, if present, may be removed, for example by disassembly, orby being separated from a remainder of lever 6052 at a weakened portion6060. In this configuration, articulation is preserved or providedbetween vertebrae 300 and 302, at hinge 6054.

With reference to FIGS. 22-23, an assembly of the disclosure includes alever 6064 which engages lever points 5046, 5048, shown as projectingpins on separate portions 5042, 5044 of spacer 5040. Lever 6064 isadvantageously sized and shaped to lever vertebrae 300, 302 into acorrect relative alignment by applying an opposing force to lever points5046, 5048. After a therapeutic alignment has been carried out, portions5042, 5044 of spacer 5040 may be affixed relative to each other by afastener, for example screw 202, as shown in FIG. 23. Projections 5046,5048 may be removed after use. Alternatively, it should be understoodthat lever points 5046, 5048 may be recesses or cutouts formed inportions 5042, 5044, thereby reducing an overall profile of spacer 5040.

FIGS. 24 and 25 are analogous to FIGS. 22-23, however lever 6070 engagesone of separate portions 5042A, 5044A, of spacer 5040A, and body tissueassociated with an opposed vertebra. Lever 6070 thereby directly pushesbody tissue of vertebra 300, obtaining leverage provided by lever point5048, attached to an adjacent vertebra 302. FIGS. 22-23 and 24-25illustrate differing forms of spacer, 5040 and 5040A, in order todemonstrate additional advantageous embodiments of spacer. It should beunderstood that spacers illustrated throughout the specification may besubstituted with each other, as would be understood by one skilled inthe art.

In FIGS. 26-27, an assembly of the disclosure includes plate 420 whichis fastened to vertebra 300, and a screw 200 is rotatably connected toplate 420 and threadably engaged with vertebra 302, whereby progressiverotation of screw 200 draws vertebrae 300, 302 into mutual conformingcontact with plate 420. As with all embodiments herein, screw 200 may beany form of bone screw best adapted to the body tissue of the patientand the forces of the application, including for example a Gruberger orlag screw. One or more washers 220, for example polymeric or metallicwashers, may additionally be used to avoid damage to an implantedcomponent, or to avoid the production of debris. After the bones arereduced, plate 420 may be removed, as illustrated in FIG. 27, or mayremain in the body for a period of time, for example until vertebra 300,302 are stable in relative relation, or have fused if fusion is desired.In FIG. 27, fasteners such as screws 200 are illustrated, maintainingvertebrae 300, 302 in relative position through engagement with spacer5000. In the various embodiments, spacer 5000 is illustrated forsimplicity and clarity. It should be understood, however, that aposition of vertebrae 300, 302 may be maintained by any other known orhereinafter developed method, including for example rods, dynamicfixation, articulating plates, or cables. In embodiments, lever 6064 orlever 6070 has the form of an elongated bar.

FIGS. 28-29 illustrate a spacer 5050 having non-parallel bone engagingsurfaces 5052, 5054 forming a wedge shape. Any of the methods andapparatus of the disclosure may be used to align vertebrae 300, 302,together with a wedge shaped spacer, such as spacer 5050. FIGS. 28-29further illustrate that a therapeutic alignment is any alignment whichis beneficial for the patient, whether natural and expected, or uniqueto an individual patient.

FIG. 30 illustrates reduction of bones 300, 302, with an assembly of thedisclosure which includes a wedge shaped spacer 5050, and which uses theapparatus and method described above with respect to FIGS. 28-29,although other methods and apparatus as described herein may be used aswould be understood by a medical practitioner.

FIGS. 31-32 illustrate an apparatus and method similar to that of FIGS.26-27 as employed at the L5-S1 level. While the sacrum 310, inparticular, is illustrated here, it should be understood that vertebra300, 302, 310 may be any vertebrae or jointed surface of the body.

FIGS. 33-34 also illustrate an apparatus and method similar to that ofFIG. 26, however in this embodiment, screw 204 is provided with threads206 which engage a nut 208 at one end, and body tissue at an oppositeend. Screw 204 is passed through, or otherwise engages plate 420, forexample with a notch (not shown), and is fastened to body tissue. Twonuts secured together may be employed at the end of screw 204 forengaging a driving tool, or alternatively, screw 204 may be providedwith a tool engaging surface, for example a hex, slotted, or Phillipsengagement (not shown). If such engagement interferes with passage ofnut 208 onto screw 204, nut 208 may be passed first along the boneengaging end of screw 204. After screw 204 is engaged with body tissue,in this example sacrum 310, and plate 420, nut 208 may be driven uponscrew 204 and in engagement with plate 420, to move plate 420 and sacrum310 together, either by displacing sacrum 310, vertebra 300, or acombination of both, until alignment is achieved, as shown in FIG. 34.After alignment, screw 204 may be reduced in length to avoidinterference with body tissue, particularly after an opening in the bodyis closed. While screw 204 may be severable with a tool, for example asaw or cutting shears, one or more weakened regions 210 may be providedalong the length of screw 204 to facilitate breaking off or otherwiseremoving an excess length of screw 204.

FIGS. 35-36 illustrate reduction of vertebrae 300, 302 using an elongatescrew 212 which passes through the intervertebral space, connecting twoadjacent bones. Threads 214 are formed on a distal end of screw 212,whereby after passing through and seating within vertebra 300, screw 212may thereafter freely rotate in connection with vertebra 300. Screw head216 is sized to block movement of screw through the cortical bone ofvertebra 300. Once screw 212 is seated within vertebra 300, threads 214continue to engage tissue of vertebra 302, thereby drawing vertebra 302towards vertebra 300, and into a therapeutic alignment. After alignment,screw 212 may be left within the body, or removed, optionally replacedby alternative means for maintaining an alignment of vertebrae 300, 302.

With reference to FIGS. 37-38, assembly 128 includes a ratchet tool 6080having a lever 6082 attached to a toothed rack, pawl, or gear 6084,engaged with one or more mating racks 6086. A drawbar 6088 is releasablyengaged with vertebra 300, for example with angled teeth 6090. Moreparticularly, teeth 6090 may be slidingly positionable with respect tovertebra 300 in a first direction, and engageable with tissue associatedwith vertebra 300 in a second direction, whereby vertebra 300 may bereduced in the second direction when drawbar 6088 is engaged anddisplaced. Drawbar 6088 is connected to rack 6086, whereby movement ofrack 6086 causes a corresponding movement of drawbar 6088, whereby amedical practitioner may move an engaged vertebra in a second direction.In one embodiment, gear 6084 is rotatable about a fixed point 6092 withrespect to vertebra 300, whereby movement of lever 6082 causes reductionof vertebra 300 with respect to fixed point 6092.

In another embodiment, a second drawbar 6088A engages a second vertebra302, however in this embodiment angled teeth 6090A slidingly engagevertebra 302 in the second direction, and engage tissue associated withvertebra 302 in the first direction. Rack 6086A additionally engagesgear 6084, whereby movement of lever 6082, causes movement of drawbars6088, 6088A in opposite directions, thereby applying a moving force toboth vertebrae 300, 302, but in opposing directions, promoting relativealignment of vertebrae 300, 302.

In FIGS. 39-40, an assembly of the disclosure includes a spacer 5058having two mating portions 5060, 5062, each releasably or fixedlyengageable with a vertebra at a bone engaging surface 5064, 5066. Matingsurfaces 5070, 5072 are connected to move relative to each other, joinedby a sliding fastener 5074. An adjusting device 5076 is associated withsliding fastener 5074 to retain a relative position of mating portions5060, 5062, together with engaged vertebra 300, 302, once slidingalignment is carried out. In the embodiment illustrated, adjustingdevice 5076 includes a threaded rod 5078 engageable within a channel5080, 5082 disposed in each of mating surfaces 5070, 5072, however itshould be understood that other mechanical couplings are contemplatedwithin the disclosure, as would be understood by one skilled in the art,for example including a riveted or molded coupling. Advantageously,threaded rod 5078 may be threadingly received within mating surfaces5070, 5072, whereby a distance between vertebrae 300, 302, for exampledistraction, may also be carried out, in addition to reduction.Additional threaded nuts, or other fastener, not shown, may be usedalong threaded rod 5078 to secure adjusting device 5076 at a desiredlocation along channel 5080, 5082.

Referring now to FIGS. 41-44, a wedge shaped spacer 5090 includesrecessed or projecting engaging surfaces 5092. Spacer segments 5096,5098 are sized and dimensioned to be connectible with facing portions ofvertebrae 300, 302, and are provided with projecting or recessedengaging surfaces 5100 complementary to and mateable with engagingsurfaces 5092. As spacer 5090 is inserted between vertebra 300, 302, adistraction of vertebra 300, 302 takes place due to the wedge shape, andthe force with which spacer 5090 is inserted. When spacer 5090 issufficiently inserted, engaging surfaces 5092 and 5100 will engage,initially in connection with one of segments 5096, 5098. Subsequently,the medical practitioner displaces or reduces one or both of vertebrae300, 302 until they are therapeutically aligned. Manipulation ofvertebrae 300, 302 may be carried out by engaging segments 5096, 5098manually, or with a tool, for example using screws 218, or otherengageable surface. Alternatively, or additionally, vertebrae 300, 302may be directly manipulated.

Engaging surfaces 5092 and 5100 are positioned so that a complementaryengagement takes place when a therapeutic alignment of segments 5096,5098, and spacer 5090 has been accomplished. Accordingly, afteralignment, an engagement is made between engaging surfaces 5100 ofsegment 5098 and engaging surfaces 5092 of spacer 5090, and engagingsurfaces 5100 of segment 5096 and spacer 5090, thereby aligning all ofvertebra 300, segment 5096, spacer 5090, segment 5098, and vertebra 302.

After alignment, body tissue associated with vertebrae 300, 302, such asligaments 308, maintain engagement of segments 5096, 5098, and spacer5090. Additionally, spacer 5090 may be further secured to either or bothof segments 5096, 5098 by fasteners, including adhesives or threadedfasteners. Similarly, segments 5096, 5098 may be secured to body tissue.

FIGS. 43-44 illustrate alternative configurations of the embodiment ofFIGS. 41-42, in which segment 5096A or 5098A have a sloped shape,adapted to complement a wedge shape of spacer 5090. In this embodiment,a relative angular alignment of vertebrae 300, 302 is not changed,however an anterior-posterior displacement may be corrected.Alternatively, an increased angular alignment may be achieved by the useof an alternative angular profile of segment 5096B and or segment 5098B,as shown in FIG. 44.

With reference to FIGS. 45-46, any tool of the disclosure may be used toaddress a displacement of vertebrae 300, 302, to form an assemblyincluding a dynamic spacer 5110 which is used to distract a joint formedbetween vertebrae 300, 302. In this embodiment, exemplary tool 6010, asdescribed with respect to FIGS. 8-10, is used to reduce vertebrae 300,302. During or after the reduction of a displacement of vertebrae 300,302, distraction is achieved using spacer 5110, which may be resilient,or which may be expanded by the introduction of a gas or fluid, forexample purified air or sterile saline. After distraction, any knownform of stabilization may be employed, for example including a plate,rod, or cable. Spacer 5110, as with any spacer of the disclosure, may beprovided with a surface texture and or a releasable therapeuticsubstance which, for example, promotes bone growth.

In FIGS. 47-48, an assembly of the disclosure is illustrated which issimilar to the assembly and method described with respect to FIGS.33-34, but is configured to cooperate with spacer 5120. Moreparticularly, spacer 5120, which may have the form of any spacer of thedisclosure, is secured to plate 420 by any known means, including screw202, as illustrated. This further stabilizes vertebrae 300, 302, andmaintains a therapeutic location of a spacer. In a further embodiment, aconnection between spacer 5120 and plate 420 is partly or substantiallyrigid, preserving at least a portion of a natural range of motion.

The assembly of FIGS. 49-50 is analogous to plate 420 and screw 204, andfunctions in a like manner. However, plate 420 is connected to, orformed together with, spacer 5124. In this manner, a superior-inferiordisposition of vertebrae 300, 302 may be achieved during insertion ofspacer 5124, followed by a reduction in an anterior-posterior directionduring tightening of nut 208. This embodiment further provides forfixation of adjacent vertebrae. Either or both of extensions 5126, 5128may be flexible, to preserve at least a portion of a natural range ofmotion.

In FIGS. 51-52, a spacer 5130 includes two segments 5132, 5134, eachconnectable to a vertebra 300 or 302. Each segment 5132, 5134 has aramped surface 5136, 5138 complementary to the other, whereby assegments 5132, 5134 are moved relative to each other into an overlappedconformity, a height of spacer 5130 is increased. In this manner,segments 5132, 5134 may be assembled into an intervertebral space,engaged with body tissue of adjacent vertebrae, and then slide alongramped surfaces 5136, 5138 into overlapping conformity, wherebyreduction and distraction can both be accomplished simultaneously. Asufficient engagement may be achieved between segments 5132, 5134 andthe respective vertebrae 300, 302 to which they are attached, byprojections 5140, or adhesive. An engagement may be further secured bythe use of one or more bone screws 200.

In the embodiment of FIGS. 51-52, reduction may be carried out byapparatus and methods of the disclosure. In one embodiment, a fastener,for example screw 202 in FIG. 51, may be used to attach to a tool. InFIG. 52, vertebrae 300, 302 are aligned, and segments 5132, 5134 aresecured to each other, for example using adhesive or other fastener,such as screw 202, illustrated. In another embodiment, screw 202 mayfreely rotate within a slot (not shown) in segment 5134, and bethreadably received within segment 5132, whereby reduction anddistraction may be carried out, at least in part, by rotating screw 202.

Referring to FIGS. 53-54, an embodiment includes a spacer 5150 havingsegments 5152, 5154, each connectable to a vertebra 300 or 302. Athreaded shaft 5156 is disposed between segments 5152 and 5154,threadably engaging threaded surface 5158 of segment 5152, and slidinglyengaging surface 5160 of segment 5154. As shaft 5156 is rotated, shaft5156 engages threaded surface 5158, driving segment 5152 into alignmentwith segment 5154, thereby aligning the attached vertebrae 300, 302. Oneor more shaft collars 5162 prevents movement of shaft 5156 out ofengagement with segment 5154. An alignment of segments 5152 and 5154 maybe maintained with a fastener, for example screw 202, therebymaintaining an alignment of vertebrae 300, 302.

In some embodiments, the threaded shaft 5162 can be configured to allowfor a movable upper member (e.g., such as a movable segment 5152) tomove relative to a stationary lower member (e.g., such as a stationarysegment 5154). The movable upper member can be attached to a superiorvertebral body, while the stationary lower member can be attached to aninferior vertebral body.

In FIGS. 55-56, a plate 430 may be therapeutically used alone, or incombination with other devices of the disclosure, to provide stabilityto adjacent bones, for example vertebrae 300, 302. Plate 430 includes anexterior plate 432, and a plate extension 434 sized and dimensioned toproject into an articulating region of the joint when the exterior plateis fastened to adjacent bones. Plate extension 434 further includes oneor more projections 436 configured to pierce body tissue of adjacentbones within the articulating space, thereby securing a location of theadjacent bones, plate extension 434, and exterior plate 432, relative toeach other. In this manner, after adjacent bones, for example bones 300,302 are aligned in accordance with the disclosure, plate 430 may beinserted and secured within the intervertebral space to prevent, throughengagement of projections 436, to prevent a migration or movement ofvertebrae 300, 302 out of alignment. To further secure vertebrae 300,302 and plate 430 relative to each other, bone screws 200 may be passedthrough apertures 438. A locking screw or pin 442 (an example is shownin FIG. 78) may be attached at lock location 440, to prevent reversal ofscrews 200 after installation.

In FIGS. 57-59, spacer 5170 is connectable to plate 444 by one or morefasteners, for example one or more screws 202 (not shown). One or morebone screws 200, or other fastening method of the disclosure, may beused to secure spacer 5170 in a joint space, for example in theintervertebral space between vertebrae 300, 302, prior to connectingplate 444. In this manner, additional space is provided for accessingthe joint space. Plate 444 may thereafter be connected to spacer 5170.As an alternative to connecting plate 444 to spacer 5170 directly, oneor more bone screws 200 may be passed through apertures 446 in plate444, through apertures 5176 in spacer 5170, and into body tissue. Afterconnection to spacer 5170, plate 444 may be connected to opposing sidesof the joint, for example to cortical bone of vertebrae 300, 302. Inthis manner, an alignment of vertebrae 300, 302 may be preserved, asvertebrae 300, 302 are connected to each other at least through a mutualconnection to plate 444, and additionally via spacer 5170, eitherthrough screws 200, and or via projections 5172, or by bone ingrowth,for example through an aperture 5174 in spacer 5170. Finally, additionalsupport is achieved by connecting spacer 5170 and plate 444, asdescribed.

In FIG. 60, spacer 5170 is utilized, as described with respect to FIGS.57-59, however plate 448 is provided with one or more projections orposts 450 which mateably engage spacer 5170. In this manner, spacer 5170may be inserted to a desired depth within the joint space, and post 450may be engaged with spacer 5170 to prevent a change in angulardisposition between plate 448 and spacer 5170. In the embodiment shown,plate 448 is further connectable with one of the bones of the joint, forexample vertebra 300, however plate 448 could extend in an oppositedirection to be more easily connectable with a bone on the opposite sideof the joint, for example vertebra 302. One or more bone screw apertures446 and lock locations 440 may be provided as described herein. Afastener, for example screw 202, may be used to further engage plate 444and spacer 5170, and to prevent movement of spacer 5170 within the jointspace. Tool engagement surfaces 452, 5178 upon plate 448 and spacer5170, respectively, are configured to facilitate releasable attachmentof a surgical tool to an implanted device of the disclosure, for ease ofmanipulation.

In another embodiment of the disclosure, shown in FIG. 63, plate 456connects to spacer 5180 by a fastener as disclosed herein, or by adovetail or other shaped connection. Spacer 5180 is not provided withapertures 5176 (as shown for example in FIGS. 58 and 62), or if they arepresent, they are not required to be used. More particularly, plate 456provides for anchoring both plate 456 and spacer 5180 to the joint,using angulated apertures 458, through which bone screws or otherfastener may be passed to connect with bones of the joint, for examplevertebrae 300, 302. Reduction of vertebrae 300, 302 may be accomplishedas disclosed elsewhere herein, or plate 456 may be fastened to first onevertebra 300, and then as bone screws are subsequently rotated into boneof vertebra 302, plate 456 and vertebrae 302 are drawn together,positioning vertebrae 300, 302 into alignment.

The embodiment of FIG. 64 is similar to the embodiment of FIG. 63;however plate 460 includes one or more shaped projection 464 thatfunction to conform to the particular shape of a bone to which it isengaged, such as the sacrum, to form a better, more stable fit, and toproduce a smaller implanted profile. Locking locations 440 areadvantageously provided to prevent reversal of a fastener insertedthrough bone screw apertures 446.

In FIGS. 65-68, spacer 5200 includes two mateable segments 5202, 5204which fasten together using a ratchet interface 5206. Segment 5202 formsan intervertebral spacer portion 5208 advantageously includingprojections 5210 which engage body tissue in the joint space to reduce alikelihood of movement of bones of the joint relative to segment 5202.One or more mounting extensions 5212 extend from intervertebral spacerportion 5208 and are configured, for example with one or more apertures5236, to engage a fastener to secure segment 5202 to body tissue, forexample by passage of a bone screw 200 through mounting extension 5212and into cortical bone of one of vertebrae 300, 302.

Segment 5204 slideably engages segment 5202, formed to project into andnest within a groove 5214 on an inner face 5216 of intervertebral spacerportion 5208. Adjacent to, or incorporated within groove 5214 and matingportions of segment 5204, are ramped engagement surfaces 5218, 5220which admit passage past each other as segment 5204 is slidingly engagedwith segment 5202 to pass into an interior passage 5222 of segment 5202,and which prevent a reversal of this engagement of segments 5202, 5204.Engagement surfaces 5218, 5220 form an interference fit with respect toeach other, and are permitted to engaged successive mutually facingramped surfaces by a resilient bending of the material of segments 5202,5204. It should be understood that groove 5214 may be formed withinsegment 5204, and segment 5202 could be formed to extend thereinto.

Segment 5204 is similarly provided with an interior passage 5224,whereby the mated segments form an opening between vertebrae 300, 302,through which bone growth may therapeutically take place, for furtherstabilization, and to promote tissue health. Longitudinal projections5228 may advantageously be formed upon an upper and lower face of anintervertebral spacer portion 5230, aligned along the direction ofmateable sliding of segment 5204 with segment 5202, and similarly serveto provide a stable engagement between segment 5204 and body tissue intowhich projections 5228 project.

Segment 5204 further has one or more mounting extensions 5226 extendingfrom an intervertebral spacer portion 5230. As with mounting extensions5212, mounting extensions 5226 are configured to engage a fastener tosecure segment 5202 to body tissue, for example by passage of a bonescrew 200 through mounting extension 5212 and into cortical bone of oneof vertebrae 300, 302.

To correct for a misalignment of bones of the joint, segment 5202 isfirst securely connected to a bone of the joint, for example vertebra300, using mounting extensions 5212. Next, segment 5204 is mounted tosegment 5202 by sliding segment 5204 partially along a length of groove5214, until mounting extension 5226 contacts tissue of the misalignedbone, for example vertebra 302. Next, using any of the methods describedherein, including manually pushing vertebra 302, segment 5204 is drivenfurther into mateable engagement with segment 5202, whereby engagementsurfaces 5218, 5220 cooperate to prevent reversal of the engagement, andmaintain segments 5202, 5204 at a desired extend of mutually overlappedengagement. Through engagement with segments 5202, 5204, bones of thejoint are maintained in relative alignment. Thus secured, no additionalplates or stabilizing implants are required, although they may be usedas deemed therapeutically beneficial for the patient.

Segments 5202, 5204 may be moved relative to each other by attaching alever between segments 5202, 5204, using a method or device as describedherein.

A fastener, including for example a screw or adhesive, may be used tofurther secure segments 5202, 5204 in mutual conformity, or to securesegments 5202, 5204 to body tissue. Bone growth materials, therapeuticdrugs, or other beneficial substances may be placed within interiorpassage 5224.

Spacer 5240 of FIGS. 69-73 is similar to the embodiment of FIGS. 65-68,with certain distinctions, described herein. Elements having a similarfunction, therefore, will be similarly numbered, and reference may behad to the foregoing discussion for a description of their structure andfunction.

Segments 5242, 5244 form a sliding connection therebetween formed byinterlocking projections 5246 and recesses 5248. A variety ofinterlocking forms may be produced by interlocking projection 5246 andrecess 5248, including for example a mortise and tenon, dovetail, andhalf-dovetail type sliding joint. If a pair of interlocking projections5246, 5248 are provided, as illustrated, they may be configured tocooperate to form a secure sliding connection. For example, eachprojection may be provided with a single angular face, on relativelyopposing sides of each of two projections 5246.

As may be seen in FIGS. 72-73, in spacer 5240A, projection 5246 andrecess 5248, of segments 5242A, 5244A, are oriented to be slidable alongan axis that is transverse with respect to an anterior-posterior axis ofthe body, when extensions 5212 are secured to an anterior face ofvertebrae 300, 302. In this manner, alignment of the vertebrae may becarried out along the coronal plane, as opposed to along the sagittalplane, as illustrated for spacers 5200 and 5240, when the respectivespacer is implanted and affixed to the body. Projection 5246 and recess5248 may thus be aligned along any axis of the body, to address aparticular pathology.

Once a therapeutic alignment has been achieved, segments 5242A, 5244Aare advantageously secured in relation to each other, to preserve anintended alignment of connected bones. As may be seen in FIG. 72, anoptional set screw 5250 may be used to secure segments 5242, 5244, orany segmented device herein, or alternatively, other fasteners of thedisclosure may be used, such fasteners including adhesive. Further,ramped engagement surfaces 5218, 5220, shown in FIGS. 65-68, may beprovided. In addition, or in the alternative, other bone fixationdevices may be used in combination with spacer 5240, 5240A, or any otherdevice of the disclosure.

It should be understood that either segment 5242 or 5244 may be formedwith a projection 5246 or recess 5248, with the mating segment assumingthe alternate profile.

Referring now to FIGS. 74-78, a spacer 5260 includes a coupling formedby a groove 5262 into which a complementary projection 468 of plate 466is inserted. Groove 5262 and projection 468 may be shaped in any of avariety of mating configurations, including, as examples, a mortise andtenon, or a dovetail. It should be noted that foregoing coupling may beprovided for other assemblies of a spacer and plate, in this disclosure;likewise, spacer 5260 and plate 466 may be connected using alternatemethods of the disclosure.

In an embodiment, spacer 5260 and plate 466 are inserted into a spacebetween bones of a joint, for example in the intervertebral space, untila plate extension 470 contacts bone of the joint, for example bone ofvertebra 302. In the embodiment of FIG. 74, plate extension 470 has aprojecting shape 472 sized and dimensioned to contact a surface of thesacrum 310, as shown in FIG. 79, although projecting shape 472 may beadapted for contacting a different surface of the body, as shown forexample in plate 466A of FIG. 75.

In FIGS. 76-77, it may be seen that bone screws 200, passed throughplate apertures 474 of plate 466, may form angles along theirlongitudinal dimension that mutually converge. This is advantageous, forexample, to ensure that screws 200 obtain purchase in supportive tissue,that they do not extend vertebral body, and or that they do notinterfere with body tissue that must be protected. In FIGS. 74-75 and78, it may be seen that screws 200 may also form divergent angles. Plateapertures 474 may be formed to guide screws 200 along intended angles,or may be polyaxial, whereby the medical practitioner may choose atherapeutically effective angular disposition of screw 200, or otherfastener.

FIGS. 74-79 further illustrate that implanted devices of the disclosuremay be formed with chamfered edges 476, to facilitate implantation, andto reduce interference with body tissue. Additionally, where a screw orother fastener passes through a device of the disclosure, it isadvantageous to ensure that the fastener does not back out fromengagement with the device or body tissue, which could lead to injury orfailure of the device. FIG. 78 illustrates a locking screw or pin 442operative to prevent substantially movement of screw 200, or otherelongated fastener, in a direction reverse to an installation direction,after implantation. A reduced profile portion 478 of pin 442 admitspassage of screw 200, when pin 442 is rotated so that reduced profile478 faces aperture 474, as shown in a lower left screw of FIG. 78. Aftera head portion of screw 200 has passed reduced profile 478, pin 442 maybe rotated so that a non-reduced portion of pin 442 blocks a path ofscrew 200, as shown for the lower right screw.

FIGS. 80-84 illustrate tool 6020A, a variation of tool 6020 of FIGS.16-18, illustrated in use together with the embodiment of FIG. 74. InFIG. 80, it may be seen that tool 6020A includes handles, advantageouslyincluding a biasing element 6102, and a lock 6104 to maintain handles ina desired disposition. A pivot 6106 enables movement of handles toeffect a corresponding movement of grippers 6108, shaped and dimensionedto cooperate with tool engagement surfaces 5178, which areadvantageously formed upon spacer 5260 and or plate 466, for thispurpose.

The functions of engagement surface 6030, push rod 6026, and guide 6028have been explained with respect to FIGS. 16-18. It may further be seenthat push rod 6026 is formed with a groove 6110 engageable with aprojection of guide 6028, operative to thereby prevent rotation of pushrod 6026 and connected engagement surface 6030. Additionally visible isan internally threaded collar 6112, cooperative with a threaded externalportion 6114 of push rod 6026, threaded collar 6112 rotatably fixedwithin support 6116 to advance or withdraw push rod 6026 to effectuatemovement of contacted body tissue. A proximal tool engaging end 6118 ofthreaded collar 6112 may be engaged and driven by a tool, for example apowered drill or t-handle, to rotate collar 6112. As rotation andreduction take place along the same axis, control of the reduction isoptimized.

In FIGS. 16-18, a threaded connection 6024 is formed between tool 6020and spacer 5030. In the embodiment of FIGS. 80-84, grippers 6108 engagean external surface of spacer 5260. Alternatively, both grippers 6108and threaded connection 6024 may be formed. FIG. 81 illustrates anassembly of spacer 5260 and plate 466 gripped by tool 6020A. In FIG. 82,tool 6020A has been used to push the assembly into a disc space formedbetween vertebra 300 and sacrum 310. Subsequently, screws 200 have beeninserted into the caudal vertebra, or sacrum 310. In FIG. 83, engagementsurface 6030 has been advanced, through rotation of threaded collar6112, to engage and urge vertebrae 300 posteriorly with respect tosacrum 310, into therapeutic alignment. In FIG. 84, one or more screws200 are inserted into the cephalad bone, vertebra 300, to thereby fix analignment of vertebra 300 and sacrum 310.

FIGS. 85A-85C depict a method of inserting a spacer in accordance withthe disclosure. In FIG. 85A, adjacent vertebrae 300, 302 are beingdistracted. In some embodiments, the vertebrae are overdistracted toprovide space for a spacer, such as any of those shown in the aboveembodiments. In FIG. 85B, after overdistracting the vertebrae, vertebra302 can be aligned with vertebra 300. Any of the devices, systems andmethods discussed above can be used to align the upper vertebra 302 withthe lower vertebra 300. In FIG. 85C, after alignment of the vertebrae, aspacer 5000 with surface protrusions can be inserted into the disc spacebetween the overdistracted vertebrae. Once the spacer is inserted intothe disc space, the vertebrae 300, 302 can be compressed over thespacer, thereby completing the surgical procedure.

FIG. 86 depicts a side view of a combinable spacer 5040, plate having anupper lip 5055 and fasteners 202 of the disclosure. Advantageously, theupper lip 5055 of the plate can contact the upper vertebra 300, suchthat when the combined spacer and plate is forced anteriorly, the upperlip 5055 can help to push the upper vertebra 300 into alignment with thelower vertebra.

FIG. 87 depicts a side view of an alternative plate and spacercombination, similar to that shown in FIG. 34. In this embodiment, oneor more screws 200 can be provided through the plate 420. The screws 200can be aligned such that at least one enters a vertebral body, while atleast one other enters into a disc 306.

The devices and methods of the disclosure enable delivering and implantand reducing spondylolisthesis from an anterior approach, although otherapproaches are possible. More particularly, the disclosure provides fordelivering an implant and reducing the spondylolisthesis using a singletool, thereby at least reducing separate approaches into the body, andreducing time required for the procedure, for the benefit of the patientand the medical practitioners, while reducing risks and costs.Additionally, by performing insertion and reduction using a singleimplant, and by using a single tool, accuracy is improved, andmanipulation of body tissue is minimized.

Spacers, plates, and fasteners of the disclosure may be formed withbiocompatible materials, of sufficient purity, including for examplePEEK (polyether ether ketone), titanium, stainless steel, or a cobaltchromium alloy. Other polymers, metals, alloys, or composite materialsmay alternatively be used, as known in the art, or hereinafterdeveloped. A radiopacifier may be added to devices of the disclosure toimprove visibility under imaging. Devices of the invention may be formedby extrusion, milling, forging, casting, molding, or any other methodadvantageously used for the materials selected and the structureintended.

It should be understood that, in the various embodiments illustrated anddescribed herein, an assembly may include any or all of a spacer, plate,tool, and or fasteners, and although all such elements may be shown in aparticular illustration, for brevity and compactness, one or more suchelements may be eliminated in a particular medical application, as wouldbe understood by one skilled in the art. For example, an implant such asa spacer may not require separate fasteners. Alternatively, a disc 306may be healthy, and not in need of replacement, or a spacer may be usedwithout a plate.

All references cited herein are expressly incorporated by reference intheir entirety. There are many different features to the presentinvention and it is contemplated that these features may be usedtogether or separately. Unless mention was made above to the contrary,it should be noted that all of the accompanying drawings are not toscale. Thus, the invention should not be limited to any particularcombination of features or to a particular application of the invention.Further, it should be understood that variations and modificationswithin the spirit and scope of the invention might occur to thoseskilled in the art to which the invention pertains. Accordingly, allexpedient modifications readily attainable by one versed in the art fromthe disclosure set forth herein that are within the scope and spirit ofthe present invention are to be included as further embodiments of thepresent invention.

What is claimed is:
 1. A device for therapeutically aligning twomisaligned bones on opposite sides of a joint space, comprising: a firstsegment having a mounting extension and an intervertebral spacer portionconfigured to be disposed in the joint space; a second segmentconfigured to mate with the first segment, the second segment includingan aperture; a first fastener configured to be received in the mountingextension; and a second fastener configured to be received in theaperture.
 2. The device of claim 1, wherein the first segment and thesecond segment fasten together.
 3. The device of claim 2, wherein thefirst segment and the second segment fasten together via a ratchetinterface.
 4. The device of claim 1, wherein the first segment includesprojections to engage the joint space.
 5. The device of claim 1, whereinthe second segment is configured to slidably engage the first segment.6. The device of claim 5, wherein the second segment is configured tonest into a groove on an inner face of the intervertebral portion. 7.The device of claim 6, wherein the groove includes engagement surfaces.8. The device of claim 7, wherein the engagement surfaces engage thesecond segment.
 9. The device of claim 8, wherein the engagementsurfaces are ramped.
 10. The device of claim 9, wherein the engagementsurfaces are configured to provide an interference fit between thesecond segment and the intervertebral spacer portion.
 11. A device fortherapeutically aligning two misaligned bones on opposite sides of ajoint space, comprising: a first segment having a plurality of mountingextensions and a U-shaped intervertebral spacer portion configured to bedisposed in the joint space; a second segment configured to mate withthe first segment, the second segment including an aperture; a first setof fasteners each configured to be received in one of the plurality ofmounting extensions; a second fastener configured to be received in theaperture.
 12. The device of claim 11, wherein the first segment and thesecond segment fasten together.
 13. The device of claim 12, wherein thefirst segment and the second segment fasten together via a ratchetinterface.
 14. The device of claim 11, wherein the first segmentincludes projections to engage the joint space.
 15. The device of claim11, wherein the second segment is configured to slidably engage thefirst segment.
 16. The device of claim 15, wherein the second segment isconfigured to nest into a groove on an inner face of the intervertebralportion.
 17. The device of claim 16, wherein the groove includesengagement surfaces.
 18. The device of claim 17, wherein the engagementsurfaces engage the second segment.
 19. The device of claim 18, whereinthe engagement surfaces are ramped.
 20. The device of claim 19, whereinthe engagement surfaces are configured to provide an interference fitbetween the second segment and the intervertebral spacer portion.